Tempo is preparing for a future network upgrade with the implementation of TIP-1020, a new precompiled contract for efficient on-chain signature verification.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

// TIP-1020 introduces a precompile for signature verification.
// This contract demonstrates how to call it to verify a message signature.

contract SignatureVerifier {
    // The precompile is proposed to live at address 0x0A.
    address constant SIG_VERIFY_PRECOMPILE = address(0x0A);

    // Verifies a signature and returns the signer's address.
    // Reverts if the signature is invalid.
    function verify(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public view returns (address) {
        // The precompile expects a tightly packed 97-byte input:
        // 32 bytes for the hash
        // 1 byte for v
        // 32 bytes for r
        // 32 bytes for s
        bytes memory input = abi.encodePacked(hash, v, r, s);
        address recoveredAddress;

        // Use assembly to make a staticcall to the precompile.
        assembly {
            // staticcall(gas, to, in, insize, out, outsize)
            // `gas()` forwards all available gas.
            // `SIG_VERIFY_PRECOMPILE` is the target address.
            // `add(input, 0x20)` points to the start of the data in `input`.
            // `97` is the size of our input data.
            // `recoveredAddress` is the memory location for the output.
            // `32` is the expected size of the output (an address padded to 32 bytes).
            if staticcall(gas(), SIG_VERIFY_PRECOMPILE, add(input, 0x20), 97, recoveredAddress, 32) {
                // Success: The `recoveredAddress` variable now holds the result.
                // The EVM returns addresses as 32-byte values, so no masking is needed here.
            } else {
                // Failure: The signature was invalid, so the precompile reverted.
                // We revert the entire call to signal the failure.
                revert(0, 0);
            }
        }

        // Return the address recovered from the signature.
        return recoveredAddress;
    }
}